/*
 * The contents of this file are subject to the terms 
 * of the Common Development and Distribution License 
 * (the "License").  You may not use this file except 
 * in compliance with the License.
 * 
 * You can obtain a copy of the license at 
 * glassfish/bootstrap/legal/CDDLv1.0.txt or 
 * https://glassfish.dev.java.net/public/CDDLv1.0.html. 
 * See the License for the specific language governing 
 * permissions and limitations under the License.
 * 
 * When distributing Covered Code, include this CDDL 
 * HEADER in each file and include the License file at 
 * glassfish/bootstrap/legal/CDDLv1.0.txt.  If applicable, 
 * add the following below this CDDL HEADER, with the 
 * fields enclosed by brackets "[]" replaced with your 
 * own identifying information: Portions Copyright [yyyy] 
 * [name of copyright owner]
 */
// Copyright (c) 1998, 2007, Oracle. All rights reserved.  
package oracle.toplink.essentials.platform.database;

import java.io.StringWriter;

import oracle.toplink.essentials.expressions.ExpressionOperator;
import oracle.toplink.essentials.queryframework.ValueReadQuery;

/**
 * <B>Purpose</B>: Provides DB2 Mainframe specific behaviour.<P>
 * <B>Responsibilities</B>:
 * <UL>
 *      <LI>Specialized CONCAT syntax
 * </UL>
 */
public class DB2MainframePlatform extends DB2Platform {

    /**
     * INTERNAL:
     * Initialize any platform-specific operators
     */
    protected void initializePlatformOperators() {
        super.initializePlatformOperators();

        addOperator(ExpressionOperator.simpleLogicalNoParens(ExpressionOperator.Concat, "CONCAT"));
    }

    /**
     * INTERNAL:
     * Build the identity query for native sequencing.
     */
    public ValueReadQuery buildSelectQueryForNativeSequence() {
        ValueReadQuery selectQuery = new ValueReadQuery();
        StringWriter writer = new StringWriter();
        writer.write("SELECT IDENTITY_VAL_LOCAL() FROM SYSIBM.SYSDUMMY1");

        selectQuery.setSQLString(writer.toString());
        return selectQuery;
    }
}
